静脉免疫球蛋白对新生儿脐带血单核巨噬细胞吞噬功能的影响

Study on the effect of intravanous immunoglobulin on the phagocytosis of neonatal umbilical cord blood monocytes/macrophages

目的通过研究静脉免疫球蛋白(IVIG)对脐带血单核巨噬细胞吞噬功能的影响,探讨IVIG对新生儿的免疫抑制作用。方法将分离培养后新生儿脐带血和成人外周血单核巨噬细胞与异硫氰酸荧光素标记的葡聚糖(FITC_dextran)孵育,利用流式细胞技术检测单核巨噬细胞的FITC_dextran阳性细胞比率和相对荧光密度。结果加入IVIG处理培养的新生儿脐带血和成人外周血单核巨噬细胞的FITC_dextran阳性细胞比率和相对荧光密度均明显降低,但是新生儿脐带血降低更明显。结论IVIG可以明显抑制脐带血单核巨噬细胞的吞噬功能,此种抑制作用可能与IVIG抑制脐带血单核巨噬细胞表面的某些受体有关。

Objectives It was presumed that immune inhibitory function of intravenous immunoglobulin（IVIG） was produced by changing phagocytosis of the monocyte/macrophages. In order to explore the inhibitory mechanism of IVIG on neonatal immune function, we investigate the phagocytosis of umbilical cord blood monocyte/macrophages（Mo/M0）. Methods eight full-term neonates with normal Apgar score were selected randomly from the delivery room of Xinhua Hospital as subjects（average age was 40 weeks）, their Mo/ Mφ in the umbilical cord blood were studied. And 8 healthy adults were selected, their Mo/ Mφ in the peripheral blood were studied as control. The Mo/Mφ was separated, and DMEM culture medium was added into the control group, and each ml of DMEM culture medium was added by freezing human immunoglobulin to the subjects. After being cultured for 72 hour, the Mo/ Mφ were incubated with fluorescein isothiocyanate-dextran（FITC-dextran） . The expression of FITC-dextran and the percentage of positive cell were tested with flow cytometry. The results were compared with those of adults. Results The percentage of positive cell in the umbilical cord blood without IVIG stimulating was 94.17±1.56, and the expression of FITC-dextran was 546.28±17.29. Whereas, the percentage of positive cell and FITC-dextran relative fluorescence intensity in the umbilical cord blood cultures with IVIG significantly decreased in 56.04±5.07 and 345.86±24.00, respectively. The differences were statistically significant（P〈 0.01）. The percentage of positive cell and FITC-dextran relative fluorescence intensity in the peripheral blood in adults were also obvi- ously decreased. Whereas, the percentage of positive cell in umbilical cord blood was 0.63, and 0.78 in the peripheral blood with significant difference between two groups（P〈0.01） . FITC-dextran relative fluorescence intensity in the umbilical cord blood was 0.60,but was 0.86 in the peripheral blood of adults also with significant difference between two groups（P〈0.01） . Conclusions IVIG can inhibit the phagocytosis of umbilical cord blood monocyte/macrophages and it might be related to the inhibitory effect of IVIG on some receptors of monocytes/macrophages.